This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. More than 80 percent of global transmission of HIV infection occurs via mucosal routes. The ability of vaccines to induce mucosal immunity may be required for protection against HIV infection and the immunodeficiency syndrome that emerges after infection. Various AIDS vaccine candidates are currently under development, each with potential advantages and disadvantages. DNA vaccines have features that make them attractive vaccine candidates for HIV and the combination of DNA vaccination plus recombinant vaccinia is one of the favored approaches in AIDS vaccine development.